Absorbent articles such as a disposable diaper are known. An absorbent article, for example, includes an absorbent main body, a pair of side flaps which extend toward outer sides from both end portions in a width direction of the absorbent main body, an elastic member which is joined in between the pair of side flaps in the absorbent main body, and leakage barriers which extend along a longitudinal direction on both sides of a central portion in the width direction on one surface of the absorbent main body. In such an absorbent article, for example, the pair of side flaps are folded over the absorbent main body.
As the folding method of such an absorbent article, a folding method of a disposable diaper is disclosed in Patent Literature 1. In Patent Literature 1, the folding method is disclosed in which the pair of side flaps are folded at folding positions which extend along the longitudinal direction on the outer side of the both end portions in the width direction of the absorbent body. Further, the folding method is further disclosed in which thin portions are formed at positions in the width direction in the absorbent body, and the absorbent article is folded at folding positions which extend along the longitudinal direction and is positioned at the thin portions.